Lift truck attachment with upper and lower clamping assemblies



Mal'Ch 23, 1965 D. B. CHASE ETAL LIFT TRUCK ATTACHMENT WITH UPPER AND LOWER CLAMPING ASSEMBLIES 3 Sheets-Sheet l Filed Oct. 24, 1961 ATTORNEY March 23, 1965 D. B. CHASE ETAL 3,174,639

LIFT TRUCK ATTACHMENT WITH UPPER AND LOWER CLAMPING ASSEMBLIES Filed oct. 24, 1961 s sheets-sheet 2 'ATTORNEY March 23, 1965 D, B. CHASE ETAL 3,174,639

LIFT TRUCK TTACHMENT WITH UPPER AND LOWER CLAMPING ASSEMBLIES Filed Oct. 24, 1961 5 Sheets-Sheet 3 Mdm A TTORNEY United States Patent O 3,174,639 LIFT TRUCK ATTACHMENT WITH UPPER AND LOWER CLAMPING ASSEMBLIES Delmar B. Chase and Philip W. Ceeley, Royal Galt, Mich., assigner-s to General Motors Corporation, Detroit, Mich., a corporation of Delaware Filed ct. 2li, 19st, Ser. No. 147,323 Claims. (Cl. 214-653) This invention relates to material handling, and more particularly to apparatus for transporting large panel sections in bundled fashion from one racked location to another.

In handling large automotive body panels for shipping, the past practice has been to transport the-m from racked positions in warehouses to box car loading sites. A large crew of workmen is required at the carloading dock to lift the individual panels from their racked position at ground level and pass -them through the freight car door to other workmen inside who place the panels in appropriate elevated supports for shipping. T h-is method is not only time consuming and wasteful of labor, but leads to damage of the metal panels by unavoidably scraping one against another during the loading process. When the box car arrives at its destination, the process must be reversed for unloading. Mechanical aids commonly used to transport and lift boxed or crated articles, such as industrial lift trucks, are not presently provided with attachments capable of handling a plurality of loose panel sections of the type contemplated. The present invention concerns such an attachment.

In accordance with the invention, a conventional industrial lift truck having lift and tilt capabilities is modified to t-he extent necessary to accommodate the inventive attachment. The hydraulic system of the attachment is coupled to the existing hydraulic system of the truck so that it cooperates with the tilt and litt mechanism thereof. A single bolt and lug arrangement lock-s the attachment onto the front of the truck mast. A separate control panel is mounted adjacent the drivers compartment of the lift truck which controls the three ymajor movements of the attachment which may be made either individual-ly or simultaneously to accommodate panels of various sizes.

Further, such panels are usually arranged serially in a steel rack which allows the unsupported upper -portion to lean or Vfan out while the lower portion is held by the rack. This makes it diiiicult to band the panels into a bundleA Our invention allows the operator .to straighten the panels to a vertical position and to transport them in such a condition, banded or un'banded, all as par-t of the lifting operation.

Other objects of the invention will be more apparent from lthe description of the apparatus and accompanying methods hereinafter related together with the drawings to which reference may be made for an embodiment of the present invention wherein:

FIGURE l is a perspective view showing the upper boom lfully raised on the triple Vlift mast with both the upper and lower right and left grabs fully extended;

FIGURE 2 is a `side View showing the upper boom in the lowered portion;

FIGURE 3 is a sectional view taken along the line 3 3 of FIGURE l;

FIGURE 4 is a schematic showing the attachment approaching racked panels that are to be lifted;

FIGURE 5 shows the attachment in a secured position just prior to lifting a banded bundle; and

FIGURE 6 is a schematic showing the handle lifted into a transporting position.

Referring now to FIGURE l, the attachment includes an upper boom assembly having right and left grabs 25 and 26 mounted on telescopic members 30 for individual ,l74,639 Patented Mar. 23, 1965 lCe actuation in a lateral direction by hydraulic cylinders 38. The telescopic tilt beam 28, functioning as hereinafter described, moves in conjunction with telescopic members 39. The upper boom assembly is raised and lowered by a triple lift mast assembly.

The mast assembly is constructed of channel H frames lli, 2G and 22 and carriage 24 arranged to slide on rollers 23 for raising and lowering the boom assembly. Carriage 24 carrying the boom assembly is powered by hydraulic cylinders 34 through a sprocket land chain arrangement 21 and is guided vertically by H frame 22 Iwhich in turn is powered by hydraulic cylinder 44 through a separate sprocket and chain `arrangement 19. H jframe 22 is guided in H kframe 20 and the -t-wo are raised or lowered together by cylinder 44 which directly powers H frame 2li at juncture 29. H tra-me 18 guides the H frame 20 as well as providing isupport for the lower grab assembly and mounting face plate 46.

The lower grab assembly includes right and Ileft grabs 14 and 16 mounted on the ends of telescopic members 32 which are secured at the other ends to the outwardly extending brackets 35 on H frame 1S and project laterally through rearwardly extending end flanges 36 Ion the baeking plate 49. Hydraulic cylinders 48 lare also mounted at one end on the brackets 35 with the piston rods projecting laterally through the end flanges 36 and operatively connecting with the grabs 14 and 16. A pick-upI lip lil extends outwardly from backing plate 49 and between the right and left grabs land may include platforms of rubber, or the like, to :serve as `a bearing surface for the panel edges. Right `and left grabs 14 and 16 and the tilt beam face 2S may also be faced with rubber. The hydraulic lines 42 are broken away in FIGURE l, but they extend to a control panel 55 mounted -for easy access by the truck operator as shown in FIG. 2. Referring to FIGURE 2, the upper grab assembly is shown in the 'lowered position with the raised position being illustrated by dot-dash lines. The attachment is mounted on the mast 54 of `an industrial truck 51. The truck mast S4 is shown in the vertical position but may be tilted vforwardly or baclcwardly about a pivotal location on the truck frame, indicated generally by the reference numeral 53, by means of a conventional tilting mechanism 52. Mounted lfor vertical movement on the mast 54 is a conventional load supporting carriage mechanism, designated generally by the lift plate portion 10. Face plate 46 on H frame 18 has a downwardly extending lug 11 cooperating with the Vlift plate lil to mount the attachment on the truck mast. Bolt 12 passes through the :face plate 46 to threadably secure the attachment from shitting. The entire attachment is raised or lowered upon actuation of the carriage mechanism or tilted back wardly or forwardly with the truck mast by operating the normal truck mast controls. In addition, actuation yof the attachment power cylinders 34, t4 to raise or lower the attachment mast and cylinders 38, 4S to extend or close the upper and lower grab assemblies is controlled by the control panel S5 mounted on post 45 adjacent the operations `compartiment of the lil-ft truck. It is intended that the existing hydraulic system of the truck be used to operate all of the hydraulic cylinders of the attachment as well 'as the normal lift Vand tilt mechanism of the truck itself. With the upper boom structure lowered in the position shown in FIGURE 2. the entire boom assembly is 221/2 inches above the lloor; while in the raised position, the upper boom structure is 1221/2 inches above the floor. With the upper and lower right and left grabs 14, 16, 2S and 26 in the collapsed position, a minimum dimension of 7S inches is obtained, while in the extended position, a maximum of ll() inches is possible. Such dimensions are not a delim-itation of the apparatus to which crit-ical signiiicance is attached, but serve only to provide a general comparison. The hydraulic cylinders of the 3 attachment may be actu ated selectively `or together. Naturally, cylinders 34 are not actu-ated independently. In raising the boom, they may precede cylinder 44 until fully extended whereupon cylinder `44 lifts mast Iframes 20 and 22 until the boomis `at maximum height.

In FIGURE 3 the mounting arrangement between the lift truck and attachment is illustrated in more detail. The assembly procedure is as follows. With the attachment standing freely Vin a floor position, the lift truck is brought up behind the plate 46. The operator then tilts the truck mast forwardly until the upper edge of the lift plate dips below the lug 1-1 or he lowers the carriage mechanism, whichever is convenient. Then by easing forward and simultaneously tipping the mast back to a more vertical position, or by simply raising the carriage mechanism, the weight of the attachment will be transferred from Ithe floor to the truck. Bolt 12 is then inserted to secure the assembly `as shown.

Assuming ythat the operator desires to transport a plurality of panels with the subject attachment as illustrated in FIGURE 4, the novel -method used is as follows: By first approaching the panels, as shown, with the upper boom raised to a suflicient height to clear the top of the panels and with both the upper `and lower right and left side grabs extended suficiently to clear the sides of the panels, the fact that the top of the panels -lean in one direction further than in the other, or that the base of the panels is confined in .a rack, such as rack 47, and the top is fanned out, or that the base is spread and the top is closed, will make no difference since the operator can easily compensate for any of these conditions by merely adjusting individually or in combination the right rand ieft side grabs 14, 16, and 26, or the triple lift attachment mast. After the proper adjustments,l thexoperator then positions the truck -so that thep-ick-up lip 40 is beneath the exposed, overhanging. edges of the racked panels which extend normal to the .face plate 46. The exposed edges are aligned `and constitute `a rearward pick-up surface, generally designated by numeral 60, for cooperation with lip 40. The boom is then in la position over the panels. At this stage, the .panels `are loosely situated land perhaps leaning, as `before mentioned, in one direction or another. The operator then positions the lower right and left grabs 14 and 16 to secure the lower portion of the panels from lateral shifting. Next, he straightens the upper portion of the panels by lowering the boom around the group and by actuating the right `and left side `grabs 25 and 26. With the panels held in a vertical position, shown in FIGURE 5, they may be banded if desired. The operator lifts the bundle from the racked position by actuating the conventional tilt mechanism ofthe ilift truck Ithus tilting the truck mast rearwardly, swinging the attachment and bundle about the truck mast pivot 53 located to the rear of the mast.

The -function of the tilt beam 28 in 'connection with the normal disposition of the panels becomes important here. With the boom collapsed, shown in FIGURE 5, the bundle is only ligh-tly held by side grabs 14, 16, 25 and 26, thus the rack 47 carries 4the entire weight. By actuating the truck mas-t tilting mechanism, the tilt beam 28 is pulled back against the front @face of the bundle thereby tilting itprearwardly out of the rack and into full load bearing relationship with the pick-up lip 40 and `into the transporting position shown in FIGURE I6. Hence, it is seen that the Iindividual panels are lodged between the pick-up lip 4t) and the contines of the upper boom and are prevented from slipping outwardly or becoming disarranged by the restraining action of the tilt beam. The bundle is then transported to la box car, yor the like, and the `above-outl-ined steps reversed for lowering into a shipping position.

If it is desirable toI accommodate bundles of different size in a direction normal to face plate 45t, the upper right and left grabs 25 and 26 may be manually extended by relieving pins 27 in holes 50shown in FIGURES 1 and 2,V and merely pulling the grabs 25 and 26 and tilt beam 28 outwardly. It has been found that bundles varying in thickness within a reasonable range may be picked up even though the above-described adjustment has not been made with a. high degree of precision. For example, instead of tilting rearwardly with the truck mast, the whole attachment may be raised slightly by lifting the carriage mechanism of the truck. rl`his Imovement will raise the entire attachment relative to lthe 'panels with lip 40 engaging on the pick-up surface 60 tilting the top of the bundle forwardly against the tilt beam 2S of the still surrounding upper boom assembly. The bundle may be carried in this slanting position, or carried upright if sufficient rearward travel is left in the truck mast. The rack 47 does not confine the bundles so tightly as to prevent a slight forward tilt. In any case, it is obvious that if necessary, the rack itself may be tilted.

While the preferred `embodiment of the invention has been described in order tov explain the principles of the invention, it is to be understood that modifications in structure vmay lbe made by the exercise of skill in the art within the scope of the invention which is no-t to be regarded as limited by the detailed description of the preferred embodiment.

e claim:

l. Apparatus for handling aligned' racked articles comprising irst means for forwardly engaging a rearward pickup surface formed by the aligned lower edges of said articles when in racked position, laterally telescoping second means formed as a substantially rigid enclosure, third means for actuating said second means in a lateral direction for fully surrounding the upper ends of said articles, and fourth means for tilting said articles out of racked position and into supported position by saidY first and second mentioned means.

2. Apparatus `as described in claim l wherein means are provided for causing said second means to move vertically relative to said first means.

3. A device of the character described adapted to be attached to an industrial truck or like vehicle having lift and tilt means comprising:

an upper boom assembly;

a mast assembly supporting said boom assembly for movement between raised and lowered positions;

a lower grab assembly secured to the lower portion of said mast assembly; and

said upper boom assembly having right and left grab members each having outwardly slidable extensions thereon, telescopic members secured to said mast assembly and movably mounting said grab members, means for actuating said telescopic members, and adjustable beam means extending between said right and -left grab members for fully surrounding the upper portion of articles.

4. The device as described in claim 3 wherein said lower grab assembly comprises movable right :and left grab members, telescopic members attached to said mast assembly and extending between said right and left grab members and providing movable support therefor, means for actuating said telescopic members, and forwardly extending lip means to provide a lower support surface for said articles.

5. A device of the character described, adapted to be attached to an industrial truck or like vehicle having lift and tilt means comprising:

an upper boom assembly;

a mast assembly supporting said boom assembly for movement between raised and lowered positions;

a lower grab assembly secured to the lower portion of said mast assembly;

said upper boom assembly having right and left grab mem-bers each having outwardly slidable extensions thereon, telescopic members secured to said mast assembly and movably mounting said grab members, means for actuating said telescopic members, and adbers, and forwardly extending lip means to provide FOREIGN PATENTS a lower support surface for said articles. 1 106 182 Fran@ July 13 1955 

1. APPARATUS FOR HANDLING ALIGNED RACKED ARTICLES COMPRISING FIRST MEANS FOR FORWARDLY ENGAGING A REARWARD PICKUP SURFACE FORMED BY THE ALINGED LOWER EDGES OF SAID ARTICLES WHEN IN RACKED POSITION, LATERALLY TELESCOPING SECOND MEANS FORMED AS A SUBSTANTIALLY RIGID ENCLOSURE, THIRD MEANS FOR ACTUATING SAID SECOND MEANS IN A LATERAL DIRECTION FOR FULLY SURROUNDING THE UPPER ENDS OF SAID ARTICLES, AND FOURTH MEANS FOR TILTING SAID ARTICLES OUT OF RACKED POSITION AND INTO SUPPORTED POSITION BY SAID FIRST AND SECOND MENTIONED MEANS. 